The 31-year-old is to vacate his position as co-anchor on Ireland Live in December, less than a year after being unveiled as one of the new station's big-name signings.

Donoghue, who also presents Newstalk Breakfast with Ivan Yates, handed in his resignation last Friday but was offered a new role making documentaries for the series 'Insight'.

Staff at the embattled ­channel were also told ­yesterday that former TV3 news anchor Alan Cantwell is to join the ­newsroom.

Sources insisted that Cantwell will be a news ­editor and will not be replacing ­Donoghue on air.

"Just to let you know that Alan Cantwell will be joining us in the newsroom tomorrow, Tuesday. He will be shadowing some shifts on the newsdesk, please make him feel welcome," an email to staff said.

Donoghue is currently on Newstalk from 7am-10am each weekday before ­switching to television at 10pm three nights a week. His co-anchor is Alison Comyn.

His decision to leave the slot is a major blow for UTV Ireland which is struggling to compete with RTÉ and TV3.

Latest figures for Ireland Live show it is achieving audiences of less than 40,000.

"Last week I resigned from Ireland Live News on UTV ­Ireland. I've been working across 19-hour days now for a year and something had to give," Donoghue told the Irish Independent. "I have to focus on Newstalk Breakfast which has always been my full-time job.

"However, I'm happy about the subsequent offer of the Insight programme from ­management at UTV Ireland.

"I've made some great friends and worked with some brilliant colleagues, particularly Alison Comyn," he added.

In a statement, UTV Ireland's Head of Channel, Mary Curtis, confirmed that Donoghue will step down in "early December".

"Thereafter, Chris will work with UTV Ireland on our ­successful documentary series, 'Insight' - a series of special programmes produced by the Ireland Live News team.

"We fully understand Chris's decision and we are delighted to be continuing our ­relationship with such an exceptional ­journalist and broadcaster."

His departure comes just weeks after news that the ­station has decided not to ­renew Pat Kenny's talk show 'In the Round' for a second season.